| 1 | /* |
| 2 | * Copyright 2001-2007 Stephen Colebourne |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.joda.time.field; |
| 17 | |
| 18 | import org.joda.time.Chronology; |
| 19 | import org.joda.time.DateTimeField; |
| 20 | |
| 21 | /** |
| 22 | * Converts a strict DateTimeField into a lenient one. By being lenient, the |
| 23 | * set method accepts out of bounds values, performing an addition instead. |
| 24 | * <p> |
| 25 | * LenientDateTimeField is thread-safe and immutable. |
| 26 | * |
| 27 | * @author Brian S O'Neill |
| 28 | * @see org.joda.time.chrono.LenientChronology |
| 29 | * @see StrictDateTimeField |
| 30 | * @since 1.0 |
| 31 | */ |
| 32 | public class LenientDateTimeField extends DelegatedDateTimeField { |
| 33 | |
| 34 | private static final long serialVersionUID = 8714085824173290599L; |
| 35 | |
| 36 | private final Chronology iBase; |
| 37 | |
| 38 | /** |
| 39 | * Returns a lenient version of the given field. If it is already lenient, |
| 40 | * then it is returned as-is. Otherwise, a new LenientDateTimeField is |
| 41 | * returned. |
| 42 | */ |
| 43 | public static DateTimeField getInstance(DateTimeField field, Chronology base) { |
| 44 | if (field == null) { |
| 45 | return null; |
| 46 | } |
| 47 | if (field instanceof StrictDateTimeField) { |
| 48 | field = ((StrictDateTimeField)field).getWrappedField(); |
| 49 | } |
| 50 | if (field.isLenient()) { |
| 51 | return field; |
| 52 | } |
| 53 | return new LenientDateTimeField(field, base); |
| 54 | } |
| 55 | |
| 56 | protected LenientDateTimeField(DateTimeField field, Chronology base) { |
| 57 | super(field); |
| 58 | iBase = base; |
| 59 | } |
| 60 | |
| 61 | public final boolean isLenient() { |
| 62 | return true; |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Set values which may be out of bounds by adding the difference between |
| 67 | * the new value and the current value. |
| 68 | */ |
| 69 | public long set(long instant, int value) { |
| 70 | // lenient needs to handle time zone chronologies |
| 71 | // so we do the calculation using local milliseconds |
| 72 | long localInstant = iBase.getZone().convertUTCToLocal(instant); |
| 73 | long difference = FieldUtils.safeSubtract(value, get(instant)); |
| 74 | localInstant = getType().getField(iBase.withUTC()).add(localInstant, difference); |
| 75 | return iBase.getZone().convertLocalToUTC(localInstant, false); |
| 76 | } |
| 77 | } |